connecting a compaq laptop to tv help would be much apreciated :)

ok heres the thing, i just got a new tv and i wanted to play my laptop onto it, but it seems that wen i plug it in and sort it all out, all i get is the wallpaper from the desktop on the tv, and ive tried pressing the "function" and f4 button but nothin at all happens, help?

 

You need to go into your display settings and make the tv out your primary display